Does that help?
paste more of the log. is there a section before that showing details of a block submission? could there be a problem with the transactions in the coinbase related to the devcoin payouts that come from the file it regularly downloads?
that's another thing that probably needs testing. testing blocks found before and after the boundaries of new file data.
Here are few I can find in .devcoin/debug.log
received block 65bb9b37eea3360642b5637d5ea5305ff3cdaf00acaf9c4e8baf57fcf860cbd8
Committing 11 changed transactions to coin database...
SetBestChain: new best=65bb9b37eea3360642b5637d5ea5305ff3cdaf00acaf9c4e8baf57fcf860cbd8 height=125114 log2_work=75.067766 tx=224528 date=2014-02-07 23:20:07 progress=0.072150
ProcessBlock: ACCEPTED
received block 0521b1afb4cea4a79fba7f11953e5c1a1f3dfcb64ec8d57c17a548e28a268708
Committing 7 changed transactions to coin database...
SetBestChain: new best=0521b1afb4cea4a79fba7f11953e5c1a1f3dfcb64ec8d57c17a548e28a268708 height=125115 log2_work=75.068056 tx=224531 date=2014-02-07 23:24:43 progress=0.072151
ProcessBlock: ACCEPTED
received block 0f174afcb109386fb8e25e6c3170c218653941850d8547320003f53f0564eb67
Committing 1 changed transactions to coin database...
SetBestChain: new best=0f174afcb109386fb8e25e6c3170c218653941850d8547320003f53f0564eb67 height=125116 log2_work=75.068347 tx=224532 date=2014-02-07 23:26:18 progress=0.072151
Committing 18 changed transactions to coin database...
SetBestChain: new best=d0af0a1871a72ba01e509317ec4f77f4a279610676273a5ab97957b7b1853d38 height=125117 log2_work=75.068641 tx=224539 date=2014-02-07 23:37:29 progress=0.072154
Committing 20 changed transactions to coin database...
SetBestChain: new best=efad489d53063f984226aac7475b7cb043abad6514cda3eae135ac490e9dba27 height=125118 log2_work=75.068935 tx=224550 date=2014-02-07 23:54:27 progress=0.072157
ProcessBlock: ACCEPTED
getblocks 125085 to 0000000000000000000000000000000000000000000000000000000000000000 limit 500
getblocks -1 to 0000000000000000000000000000000000000000000000000000000000000000 limit 500
keypool added key 102, size=101
keypool reserve 2
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
Flushing wallet.dat
Flushed wallet.dat 20ms
Added 1 addresses from 188.220.216.98: 12 tried, 1123 new
accepted connection 82.15.144.161:56275
send version message: version 70001, blocks=125120, us=190.120.236.179:52333, them=82.15.144.161:56275, peer=82.15.144.161:56275
Added time data, samples 4, offset -1 (+0 minutes)
Added 82.15.144.161:52333 from 82.15.144.161: 10 tried, 1159 new
Moving 82.15.144.161:52333 to tried
receive version message: version 32501, blocks=125120, us=190.120.236.179:52333, them=82.15.144.161:52333, peer=82.15.144.161:56275
connection timeout
trying connection 106.187.94.193:52333 lastseen=0.4hrs
connected 106.187.94.193:52333
send version message: version 70001, blocks=125120, us=190.120.236.179:52333, them=106.187.94.193:52333, peer=106.187.94.193:52333
Added time data, samples 5, offset -2 (+0 minutes)
nTimeOffset = -1 (+0 minutes)
receive version message: version 32501, blocks=125120, us=190.120.236.179:51827, them=106.187.94.193:52333, peer=106.187.94.193:52333
trying connection 95.87.202.189:52333 lastseen=4.5hrs
connection timeout
trying connection 94.12.52.116:52333 lastseen=4.9hrs
connection timeout
trying connection 91.121.174.223:52333 lastseen=2.6hrs
connected 91.121.174.223:52333
send version message: version 70001, blocks=125120, us=190.120.236.179:52333, them=91.121.174.223:52333, peer=91.121.174.223:52333
Added time data, samples 6, offset -1 (+0 minutes)
Moving 91.121.174.223:52333 to tried
receive version message: version 32501, blocks=125120, us=190.120.236.179:47184, them=91.121.174.223:52333, peer=91.121.174.223:52333
trying connection 162.243.208.154:52333 lastseen=0.4hrs
connected 162.243.208.154:52333
send version message: version 70001, blocks=125120, us=190.120.236.179:52333, them=162.243.208.154:52333, peer=162.243.208.154:52333
Added time data, samples 7, offset -1 (+0 minutes)
nTimeOffset = -1 (+0 minutes)
receive version message: version 32501, blocks=125120, us=190.120.236.179:59703, them=162.243.208.154:52333, peer=162.243.208.154:52333
keypool reserve 2
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
trying connection 173.69.204.230:52333 lastseen=4.8hrs
connection timeout
trying connection 46.115.143.136:52333 lastseen=4.9hrs
connection timeout
trying connection 38.118.62.165:52333 lastseen=4.6hrs
connection timeout
trying connection 38.108.113.249:52333 lastseen=4.9hrs
accepted connection 68.38.11.21:59000
send version message: version 70001, blocks=125120, us=190.120.236.179:52333, them=68.38.11.21:59000, peer=68.38.11.21:59000
Added time data, samples 8, offset -6 (+0 minutes)
Moving 68.38.11.21:52333 to tried
receive version message: version 32501, blocks=125120, us=190.120.236.179:52333, them=68.38.11.21:52333, peer=68.38.11.21:59000
Added 3 addresses from 91.121.174.223: 13 tried, 1159 new
connection timeout
trying connection 49.187.164.172:52333 lastseen=4.8hrs
connection timeout
trying connection 96.237.186.113:52333 lastseen=5.1hrs
received block 30e695568bcf94589433c4ea652ecc1935b2220ac8c4a6432165a0823c875852
Committing 10 changed transactions to coin database...
SetBestChain: new best=30e695568bcf94589433c4ea652ecc1935b2220ac8c4a6432165a0823c875852 height=125127 log2_work=75.071554 tx=224583 date=2014-02-08 01:35:27 progress=0.072159
ProcessBlock: ACCEPTED
received block 98765ac4f89e458e2c2cefcc10cc1c751571f063af48c55ec80341f847d60627
Committing 4 changed transactions to coin database...
SetBestChain: new best=98765ac4f89e458e2c2cefcc10cc1c751571f063af48c55ec80341f847d60627 height=125128 log2_work=75.071833 tx=224585 date=2014-02-08 01:36:09 progress=0.072160
ProcessBlock: ACCEPTED
connection timeout
trying connection 99.232.33.22:52333 lastseen=6.8hrs
connection timeout
trying connection 2.239.40.87:52333 lastseen=1.8hrs
connection timeout
trying connection 77.184.69.252:52333 lastseen=6.8hrs
Added 85 addresses from 198.211.105.133: 10 tried, 1205 new
connection timeout
trying connection 84.227.24.246:52333 lastseen=7.0hrs
connect() failed after select(): No route to host
trying connection 74.115.95.138:52333 lastseen=2.0hrs
connected 74.115.95.138:52333
send version message: version 70001, blocks=125128, us=190.120.236.179:52333, them=74.115.95.138:52333, peer=74.115.95.138:52333
trying connection 74.103.210.161:52333 lastseen=6.4hrs
keypool reserve 2
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
connection timeout
trying connection 99.73.124.137:52333 lastseen=4.2hrs
connection timeout
trying connection 38.108.113.249:52333 lastseen=6.5hrs
connection timeout
trying connection 106.187.94.193:52333 lastseen=2.0hrs
connected 106.187.94.193:52333
send version message: version 70001, blocks=125128, us=190.120.236.179:52333, them=106.187.94.193:52333, peer=106.187.94.193:52333
socket recv error 104
disconnecting node 106.187.94.193:52333
trying connection 68.187.211.2:52333 lastseen=2.0hrs
connection timeout
trying connection 68.187.211.2:52333 lastseen=2.0hrs
connection timeout
trying connection 2.239.40.87:52333 lastseen=1.8hrs
trying connection 113.68.109.104:52333 lastseen=2.1hrs
connection timeout
trying connection 90.130.41.14:52333 lastseen=2.7hrs
connected 90.130.41.14:52333
send version message: version 70001, blocks=125130, us=190.120.236.179:52333, them=90.130.41.14:52333, peer=90.130.41.14:52333
ThreadRPCServer method=getbalance
socket recv error 104
disconnecting node 90.130.41.14:52333
trying connection 162.242.17.178:52333 lastseen=2.5hrs
connected 162.242.17.178:52333
send version message: version 70001, blocks=125130, us=190.120.236.179:52333, them=162.242.17.178:52333, peer=162.242.17.178:52333
Added time data, samples 13, offset +3 (+0 minutes)
nTimeOffset = +0 (+0 minutes)
Moving 162.242.17.178:52333 to tried
receive version message: version 32501, blocks=125130, us=190.120.236.179:48601, them=162.242.17.178:52333, peer=162.242.17.178:52333
accepted connection 98.201.33.193:65029
send version message: version 70001, blocks=125130, us=190.120.236.179:52333, them=98.201.33.193:65029, peer=98.201.33.193:65029
Added time data, samples 14, offset -10 (+0 minutes)
Moving 98.201.33.193:52333 to tried
receive version message: version 32501, blocks=125130, us=190.120.236.179:52333, them=98.201.33.193:52333, peer=98.201.33.193:65029
ThreadRPCServer method=getinfo
keypool reserve 2
keypool return 2
CTxMemPool::accept() : accepted 5912842f1c77966b57d9976f6b1db1f208dee045f06dd8bc4ff21249e86a25fe (poolsz 1)
received getdata for: tx 5912842f1c77966b57d9976f6b1db1f208dee045f06dd8bc4ff21249e86a25fe
received getdata for: tx 5912842f1c77966b57d9976f6b1db1f208dee045f06dd8bc4ff21249e86a25fe
Flushed 1755 addresses to peers.dat 80ms
keypool reserve 2
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
trying connection 114.79.19.38:52333 lastseen=4.7hrs
Committing 3 changed transactions to coin database...
SetBestChain: new best=6f1aefce8d1606d07fd1d60f2082a10f31613dc8e7bcc6b3e43f274a265cbd94 height=125134 log2_work=75.0735 tx=224601 date=2014-02-08 02:23:54 progress=0.072161
ProcessBlock: ACCEPTED
received block 5b7fb292496a08e8b95327475e3bf06be0ffa50ca699eecdd0b132ee241c96a8
Committing 3 changed transactions to coin database...
SetBestChain: new best=5b7fb292496a08e8b95327475e3bf06be0ffa50ca699eecdd0b132ee241c96a8 height=125135 log2_work=75.073777 tx=224603 date=2014-02-08 02:29:39 progress=0.072162
ProcessBlock: ACCEPTED
ThreadRPCServer method=getin
ThreadRPCServer method=getinfo
keypool reserve 2
keypool return 2
connection timeout
trying connection 87.79.129.248:52333 lastseen=5.0hrs
14 addresses found from DNS seeds
dnsseed thread exit
Added 3 addresses from 162.243.208.154: 17 tried, 1741 new
keypool reserve 2
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
connection timeout
trying connection 217.44.32.33:52333 lastseen=0.4hrs
connection timeout
trying connection 98.201.33.193:52333 lastseen=0.4hrs
connection timeout
trying connection 118.244.207.5:52333 lastseen=0.6hrs
connected 118.244.207.5:52333
send version message: version 70001, blocks=125135, us=190.120.236.179:52333, them=118.244.207.5:52333, peer=118.244.207.5:52333
Added time data, samples 3, offset -1 (+0 minutes)
receive version message: version 32501, blocks=125135, us=190.120.236.179:60519, them=118.244.207.5:52333, peer=118.244.207.5:52333
trying connection 65.188.164.108:52333 lastseen=5.3hrs
connection timeout
trying connection 204.14.77.5:52333 lastseen=4.7hrs
connection timeout
trying connection 99.194.200.2:52333 lastseen=5.3hrs
send version message: version 70001, blocks=125135, us=190.120.236.179:52333, them=54.241.178.41:52333, peer=54.241.178.41:52333
received block 63266ac15972835220dafb25afe395f9e3a0f2882939efb85da63e72dc8e18e4
Committing 1329 changed transactions to coin database...
SetBestChain: new best=63266ac15972835220dafb25afe395f9e3a0f2882939efb85da63e72dc8e18e4 height=125136 log2_work=75.074054 tx=224605 date=2014-02-08 02:34:53 progress=0.072161
ProcessBlock: ACCEPTED
received block cf37b6038ae65c67e2430ac5f16ae56e69ed890a84a9594fc8b7766401633cc9
Committing 5 changed transactions to coin database...
SetBestChain: new best=cf37b6038ae65c67e2430ac5f16ae56e69ed890a84a9594fc8b7766401633cc9 height=125137 log2_work=75.074331 tx=224608 date=2014-02-08 02:42:53 progress=0.072162
ProcessBlock: ACCEPTED
Added time data, samples 4, offset +99 (+1 minutes)
receive version message: version 32400, blocks=125137, us=190.120.236.179:47376, them=54.241.178.41:52333, peer=54.241.178.41:52333
trying connection 50.131.171.225:52333 lastseen=5.4hrs
Added 28 addresses from 54.241.178.41: 19 tried, 1764 new
14 addresses found from DNS seeds
dnsseed thread exit
Flushing wallet.dat
Flushed wallet.dat 29ms
Added 1 addresses from 23.94.28.23: 19 tried, 1764 new
connection timeout
trying connection 122.178.217.3:52333 lastseen=1.0hrs
keypool reserve 2
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
connection timeout
trying connection 162.242.17.178:52333 lastseen=0.8hrs
connected 162.242.17.178:52333
send version message: version 70001, blocks=125137, us=190.120.236.179:52333, them=162.242.17.178:52333, peer=162.242.17.178:52333
Added time data, samples 5, offset +3 (+0 minutes)
nTimeOffset = +3 (+0 minutes)
receive version message: version 32501, blocks=125137, us=190.120.236.179:57476, them=162.242.17.178:52333, peer=162.242.17.178:52333
trying connection 98.28.46.106:52333 lastseen=5.1hrs
Added 6 addresses from 54.252.166.125: 19 tried, 1770 new
connection timeout
trying connection 198.154.60.183:52333 lastseen=2.0hrs
connected 198.154.60.183:52333
send version message: version 70001, blocks=125137, us=190.120.236.179:52333, them=198.154.60.183:52333, peer=198.154.60.183:52333
Added time data, samples 6, offset -1 (+0 minutes)
Moving 198.154.60.183:52333 to tried
receive version message: version 32400, blocks=125137, us=190.120.236.179:45486, them=198.154.60.183:52333, peer=198.154.60.183:52333
trying connection 36.83.52.243:52333 lastseen=5.4hrs
connection timeout
trying connection 200.203.173.39:52333 lastseen=5.0hrs
Added 7 addresses from 198.154.60.183: 20 tried, 1775 new
connection timeout
trying connection 114.79.19.38:52333 lastseen=5.1hrs
connection timeout
trying connection 74.115.95.138:52333 lastseen=2.0hrs
connected 74.115.95.138:52333
send version message: version 70001, blocks=125137, us=190.120.236.179:52333, them=74.115.95.138:52333, peer=74.115.95.138:52333
CTxMemPool::accept() : accepted d30b784d194878136924790cdc1fccf77ad9f15846498a664f0a69248209d905 (poolsz 1)
Added time data, samples 7, offset +3 (+0 minutes)
nTimeOffset = +3 (+0 minutes)
receive version message: version 32501, blocks=125137, us=190.120.236.179:44649, them=74.115.95.138:52333, peer=74.115.95.138:52333
trying connection 120.149.117.234:52333 lastseen=5.4hrs
This one had two before dying
received block 8fd048e1ea705befc9a1e05824def0dfc780bf3525f4255d8c8fde11282a9eaf
Committing 7 changed transactions to coin database...
SetBestChain: new best=8fd048e1ea705befc9a1e05824def0dfc780bf3525f4255d8c8fde11282a9eaf height=125139 log2_work=75.074886 tx=224623 date=2014-02-08 03:11:24 progress=0.072164
ProcessBlock: ACCEPTED
received block bde85f90140fe3315a920e3e9a655df5a7dcf2c7c301f3ed9d128493e7844a16
Committing 1 changed transactions to coin database...
SetBestChain: new best=bde85f90140fe3315a920e3e9a655df5a7dcf2c7c301f3ed9d128493e7844a16 height=125140 log2_work=75.075165 tx=224624 date=2014-02-08 03:13:41 progress=0.072164
ProcessBlock: ACCEPTED
received block 5dc796723a9bda4bc279fd341064bb8cb8ae91ba1ad6682282c7344af0031243
Committing 8 changed transactions to coin database...
SetBestChain: new best=5dc796723a9bda4bc279fd341064bb8cb8ae91ba1ad6682282c7344af0031243 height=125141 log2_work=75.075445 tx=224629 date=2014-02-08 03:21:26 progress=0.072166
ProcessBlock: ACCEPTED
connection timeout
trying connection 66.193.195.130:52333 lastseen=6.6hrs
connection timeout
trying connection 162.242.17.178:52333 lastseen=1.3hrs
connected 162.242.17.178:52333
send version message: version 70001, blocks=125141, us=190.120.236.179:52333, them=162.242.17.178:52333, peer=162.242.17.178:52333
Added time data, samples 3, offset +3 (+0 minutes)
receive version message: version 32501, blocks=125142, us=190.120.236.179:35457, them=162.242.17.178:52333, peer=162.242.17.178:52333
trying connection 95.87.202.189:52333 lastseen=4.1hrs
connect() failed after select(): Connection refused
trying connection 69.142.88.110:52333 lastseen=6.1hrs
keypool reserve 2
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
Added 4 addresses from 162.242.17.178: 17 tried, 1742 new
received block 34d6faf3c525ad233f347b4812c0f0488c80c445e3acb378ceae4150b5d69bcc
Committing 4 changed transactions to coin database...
SetBestChain: new best=34d6faf3c525ad233f347b4812c0f0488c80c445e3acb378ceae4150b5d69bcc height=125142 log2_work=75.075724 tx=224631 date=2014-02-08 03:24:16 progress=0.072166
ProcessBlock: ACCEPTED
connection timeout
trying connection 87.114.111.214:52333 lastseen=8.3hrs
connection timeout
trying connection 24.167.200.111:52333 lastseen=8.5hrs
CTxMemPool::accept() : accepted 35bdd522f61d78aaad828ce8aa2728d41b0bfc63c882308ca8d2114abc176ff5 (poolsz 1)
connection timeout
trying connection 65.60.190.183:52333 lastseen=4.0hrs
Added 2 addresses from 118.244.207.5: 17 tried, 1744 new
connection timeout
trying connection 177.99.27.220:52333 lastseen=5.8hrs
connect() failed after select(): Connection refused
trying connection 213.167.158.78:52333 lastseen=6.4hrs
connection timeout
trying connection 175.136.130.44:52333 lastseen=6.2hrs
ERROR: CTransaction::CheckTransaction() : txout.nValue negative
ERROR: CheckBlock() : CheckTransaction failed
connection timeout
trying connection 173.154.37.181:52333 lastseen=6.1hrs
connection timeout
trying connection 82.14.115.136:52333 lastseen=6.4hrs
connection timeout
trying connection 92.141.64.225:52333 lastseen=6.1hrs
connect() failed after select(): No route to host
trying connection 24.113.73.192:52333 lastseen=6.3hrs
connection timeout
trying connection 179.253.51.21:52333 lastseen=5.8hrs
connection timeout
trying connection 80.42.201.45:52333 lastseen=13.5hrs
etc. That ERROR is present before every single termination.
P2Pool is a bit easier...it's exactly the same every time:
> Error while calling merged getauxblock on http://127.0.0.1:52332/:
2014-02-07 21:08:51.551955 > Traceback (most recent call last):
2014-02-07 21:08:51.552099 > File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 577, in _runCallbacks
2014-02-07 21:08:51.552274 > current.result = callback(current.result, *args, **kw)
2014-02-07 21:08:51.552390 > File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1155, in gotResult
2014-02-07 21:08:51.552509 > _inlineCallbacks(r, g, deferred)
2014-02-07 21:08:51.552615 > File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1097, in _inlineCallbacks
2014-02-07 21:08:51.552736 > result = result.throwExceptionIntoGenerator(g)
2014-02-07 21:08:51.552848 > File "/usr/lib/python2.7/dist-packages/twisted/python/failure.py", line 389, in throwExceptionIntoGenerator
2014-02-07 21:08:51.552971 > return g.throw(self.type, self.value, self.tb)
2014-02-07 21:08:51.553082 > --- ---
2014-02-07 21:08:51.553188 > File "/home/amit/p2pool/p2pool/util/deferral.py", line 41, in f
2014-02-07 21:08:51.553301 > result = yield func(*args, **kwargs)
2014-02-07 21:08:51.553409 > File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1097, in _inlineCallbacks
2014-02-07 21:08:51.553530 > result = result.throwExceptionIntoGenerator(g)
2014-02-07 21:08:51.553640 > File "/usr/lib/python2.7/dist-packages/twisted/python/failure.py", line 389, in throwExceptionIntoGenerator
2014-02-07 21:08:51.553768 > return g.throw(self.type, self.value, self.tb)
2014-02-07 21:08:51.553879 > File "/home/amit/p2pool/p2pool/util/jsonrpc.py", line 133, in _http_do
2014-02-07 21:08:51.553994 > raise Error_for_code(resp['error']['code'])(resp['error']['message'], resp['error'].get('data', None))
2014-02-07 21:08:51.554117 > p2pool.util.jsonrpc.NarrowError: -1 CreateNewBlock() : ConnectBlock failed
then it continues on its merry way. I've watched them both and this error occurs at the same time the devcoin error shows up. After this point, P2Pool is refused connection when it tries to connect again.